Тяжелые металлы в окружающей среде
PHYTOREMEDIATION OF POLLUTED ARREA USING GMO
жүктеу/скачать 6.49 Mb. Pdf көрінісі
|
| PHYTOREMEDIATION OF POLLUTED ARREA USING GMO
Genetic engineering in phytoremediation The heavy metals remains in various ecosystems would seep into surface water, groundwa- ter or even channel into the food chain by crops growing on such a soil (Lin et al., 1998). The scien- tific community is coming up with technologies such as vitrification, phytoremediation, bioreme- diation, earth-swap, soil flushing, and solidification for remediating contaminated sites. Phytoreme- diation has been found a promising, cost-effective, aesthetically pleasing, in situ treatment technol- ogy for the remediation of heavy metal contaminants from the soil-water environment. A genetic engineering based phytoremediation strategy is being aimed to improve the performance of plants in effective removal of metals from environment (Fulekar et al., 2009). It includes the following processes related to heavy metals:Phytoextraction- the use of plants to remove contaminants, mostly roots, from soils; Phytovolatilization- the use of plants to make volatile chemical species of soil el- ements; and Phytofiltration- the use of plant roots (rhizofiltration) or seedlings (blastofiltration) to absorb or adsorb contaminants (mostly metals) from flowing water. 122 123 Genetic engineering approach has successfully facilitated to alter the biological functions of plants through modification of primary and secondary metabolism and by adding new phenotypic and genotypic characters to plants with the aim of understanding and improving their phytoremediation properties (Davison, 2005). Metal-hyperaccumulating plants and microbes with unique abilities to tolerate, accumulate and de- toxifymetals and metalloids, represent an important reservoir of unique genes (Danika, Norman, 2005). These genes could be transferred to fast-growing plant species for enhanced phytoremedia- tion (De Souza et al., 1998). Fig. 3. Genetic engineering in phytoremediation. The utility of the yeast protein YCF1, a protein which detoxifies Cd by transporting it into vacuoles has been implemented, for the remediation of Cd and Pb. Transgenic Arabidopsis thalian- aplants overexpressing YCF1 showed an enhanced tolerance and accumulated greater amounts of Cd and Pb. Tolerance and resistance in transgenics improved both for Cd and Pb as desired for ef- fective phytoremediation (Song et al., 2003). Brassica juncea was genetically engineered to investigate rate-limiting factors for glutathione and phytochelatinproduction. To achieve this Escherichia coli gshl gene was introduced. The ECS transgenic seedlings showed increased tolerance to cadmium and had higher concentrations of phy- tochelatins, -GluCys, glutathione, and total non proteinthiols compared to wild type seedlings (Ow, 1996). жүктеу/скачать 6.49 Mb. Достарыңызбен бөлісу:
|